Herbicidal compositions containing esters of chlorinated phenoxyacetic acids



Patented Feb. 27, 1951 HERBICIDAL COMPOSITIONS CONTAINING ESTERS FCHLORINATED PHENOXY- ACETIC ACIDS William W. Allen, Ambler, Pa.,asslgnor to American Chemical Paint Company, Ambler, Pa., a corporationof Delaware No Drawing. Application August 15, 1949, Serial No. 110,457

7 Claims. (Cl. 712.6)

l The present invention relates to esters of chlorinated phenoxyaceticacids, and more particularly to the esterification products of2.4-dichlorophenoxyacetic acid and 2.4.5-trichlor0- referred'to, andwhich for this reason lend themselves for herbicidal use where theconventional esters cannot be used or can only be used with attendantdanger to desired vegetation.

Another object of considerable importance is phenoxyacetic acid with theethers of ethylene. 5 to provide a new class of esters which can beglycoL I prepared very economically or inexpensively, and The primaryobject of the invention is to prowhich can be embodied or incorporatedinto vide a wholly new class of esters of chlorinated emulsio Solutions.disp of other phenoxyacetic acids, which may be used for the bilizedform in a relatively simple, inexpensive various purposes for which theacids themselves manner, an W S0 formulated c n e e y or theconventional esters have been previously applied with conventionalequipment to weeds in used but to better advantage and without the theimmediate presence of desired vegetation. shortcomings inherent in thepreviously used The present invention is based in lar e meas- 2.4-D and2.4.5-T- compounds. m'e upon the di:covery or observation that 2.4-D Atthis point, it is to be noted that Patent No. aold and 2.4.5-T acid canbe readily esterified by 2,390,941, issued December 11, 1945, to theAmermeans of the ethers of ethylene glycol, and that loan Chemical PaintCompany of Ambler, Pennthe resulting esters can be used for the samepursylvania, as assignee of Franklin D. Jones, disposes and insubstantially the same manner as closes a wholly new class of systemicor translo- I nventional esters W th h v icated herbicides containin ahalogenated Dhefest-"11g he ological volatility, which has noxymonocarboxylic aliphatic acid, salt or ester P oved such a disadvantagein the case of said thereof. The preferred halogenated products D 0r artesters. mentioned in the patent are the chlorinated It s o noted at thisPoint that a y of phenoxyacetic compounds such as 2.4-dichloroo heethers of ethylene glycol are available on the phenoxyacetic acid,2.4.5-trichlorophenoxyacetic et under the. trade-mark Cellosolves, theacid, and their conventional salts and esters. l e glycol monoethylether or 2-ethoXy Formulations having these compounds as their aholbeing referred to simply as Cellosolve, and active ingredients havebecome increasingly im-@ the others being referred to as "Cellosolvewith portant in the control of weeds, and now consti- Prefix Such t y DDyL u y tute a very important class of .selective weedhenzyl, ph y etc.,to indicate the nature killers. The conventional esters of 2.4-D and' ofthe substituent which has replaced the eth- 2.4.5-T acids are generallyconsidered'to be the 3 p. met yl Cellusolve is ethbest all-aroundsystemic selective herbicides. Ylehe glyool ono y ether methoxy However,they do have one very serious shortahol butyl cellosolve is g ycol butylether or coming or drawback Z-butoxy ethanol, etc. All the Cellosolvesare The shortcoming or drawback just referred t applicable for theesterification of 2.4-D acid and may bedesc ribed by the term biologicalvolaacid, d e result ng products are, as t by which is meant thetendency of t far as the inventor has been able to ascertain,conventional esters of 2.4-1) and 2.4.5-1 acid to n v n al ind v spossessing un qu p por seriously injure vegetation eltles Whlch renderthem Suitable for have not been applied. Conventional esters are manypurposes- At the present time, their greatknown to have exerted toxiceffects due to bioest field of usefulness ars to be in the agrilogicalvolatility at considerable distances from cultural fl points of actualapplication, and for this reason The estefifioatloh may be readilycarried out the Federal Government as well as many states P conventlohalProcedures, and no im is'made have found t necessary t issue verystringent in this application covering the esterification regulations ast t use: n labelling f ester process. The following examples are given,but formulations. Needless to state, the field of usethe invention isnot in any way i i ed thereto: fulness of such formulations has beengreatly EXAMPLE I curtailed. I

Another very important-object of the inven- 2.4-D acid (221 grams) ismixed with tion is to provide a new class of esters of. 2.4-D grams ofbutyl Cellosolve, and heated graduand 2.4.5-T acids, whichare entirelyor substanally to -180" C. in a flask equipped with a 'tially free ofthe biological volatility previously condenser to condense the evolvedwater and 66 what little'butyl Ce1losolve" is driven over by 3 the heat.After two hours, the esteriflcation is practically complete and theheating may be stopped. After the resulting ester is cooled down, thefree acid may be readily removed by washing the ester with dilutetriethanolamine solution and then with water. The purified ester may bedried by treatment with anhydrous sodium sulfate. The residual butyl"Cellosolve may be readily separated from the condensed water by heatingthe water and decanting oil the Cello solve layer. I

The butyl Cellosolve" ester of 2.4-D acid prepared in accordance withthe foregoing example is a liquid with a specific gravity ofapproximately 1,232 at 20 C. and a boiling point of 156- 162 C. at 1 mm.pressure.

EXAIHPLE II The butyl Cellosolve ester of 2.4.5-T acid is made inexactly the same way as stated under Example I, except that the quantityof 2.4.5-T acid used is 255.5 grams.

The butyl Cellosolve" ester of 2.4.5-T acid made in accordance withExample II is a liquid with a specific gravity about 1.280 at 20 C., anda boiling point of approximately 163-466 at 1 mm. pressure.

The other Cellosolve" esters of either 2.4-D acid or 2.4.5-T acid may bemade in substantially the same way, using the ether corresponding to thedesired end products. For instance, Cellosolve, methyl Cellosolve,propyl Cellosolve," benzyl Cellosolve," or phenyl Cellosolve may besubstituted in whole or in part for the butyl "Cellosolve" of Examples Iand II.

Table of properties As previously stated, the esters of the inventionare substantially free of the biological vola-' tility exhibited by theconventional esters of 2.4-D acid and 2.4.5-T acid. This can bedemonstrated in several ways. For instance, two Petri dishes, onecontaining the butoxy ethanol (butyl Cellosolve) ester of 2.4-D acid,and the other containing the conventional ethyl ester, are placed in themidst of susceptible vegetation. After an exposure of several days, itwill be seen that the vegetation surrounding the dish containing theconventional ester is dying or exhibiting marked degrees of epinasty,whereas there is no deformation or semblance of injury in the vegetationsurrounding the other dish.

Another test of the same phenomenon consists in exposing a susceptibleplant such as a tomato plant to each of the two types of esters under abell jar.

Extensive experimentation has shown that the novel esters of the presentinvention may be formulated with various vehicles including solubilizingagents, emulsifiers, dispersing agents, wetting agents, stickers, etc.In the case of certain emulsifiers or dispersing agents, mutual solventsor cosolvents may be used to advantage. Concentrated mixtures of theesters with the various vehicles may be made up, and diluted to desiredconcentrations with water, oil or other diluent at or prior to the timeof application.

Formulations containing the esters of the invention are on an acidequivalent basis generally equal in potency and effectiveness to theconventional esters but are sibstantially free of the "biologicalvolatility" which has greatly restricted the use of the conventionalesters. As in the case of the conventional esters, the phytocidal effectcan be stepped up or intensified by the addition of oils whichthemselves need not be phytotoxic. Instead of or in addition to theoils, other substances having herbicidal activity may be incorporated inthe formulation.

The following herbicidal compositions are given by way of example, thequantities being by weight:

EXAMPLE III Per cent Butoxy ethanol ester of 2.4-D acid 11.2 Butoxyethanol ester of 2.4.5-T acid 23.5 Dispersing agent 6.0 Cosolvent 4.0Heavy aromatic naphtha 55.3

EXAMPLE IV Per cent Butoxy ethanol ester of 2.4.5-T acid 47.5 Dispersingagent 10.0 Cosolvent 4.0 Heavy aromatic naphtha 38.5

EXAMPLE V Per cent Methyl Cellosolve" ester of 2.4-D acid 30 Dispersingagent 10 Cosolvent 20 Aromatic naphtha 40 EXAMPLE VI Per cent MethylCellosolve ester of 2.4-D acid 13 Dispersing agent 5 Cosolvent 5 Oil 77EXAMPLE VII Per cent Methyl Cellosolve" ester of 2.4-D acid 15 Mahoganysoap 20 Cosolvent 5 Oil 60 EXAMPLE VIII Per cent Methyl Cellosolve"ester of 2.4-D acid Atlas G9816T (polyethylene sorbitan esters of mixedfatty and resin acids) 10 The specified esters in the foregoing examplesare those which are preferred, but it is possible to utilize any one ormore of the other esters of the invention in substantially the same orequivalent proportions.

Many surface active agents are suitable as dispersing agents, and inExample III the preferred agent is Atlas G8916F, which containspolyethylene sorbitan esters of mixed fatty and resin acids, and inExample IV, the preferred agent is Antarox 13-100, which consistsessentially of polyethylene glycol oleate. As indicated, mahogany soap,which is also known as naphthenic soap, petroleum sludge soap andsulfonate naphthenate, is used in Example V. Practically any mutualsolvent or cosolvent may be used in Examples III to VII. The highmolecular weight straight chain alcohols exemplified by butanol,

In conclusion, it is to be understood that the foregoing disclosure hasbeen made rather detailed to comply with the patent statutes, and is notto restrict the invention beyond what is required by the state of theprior art.

I claim:

1. A herbicidal composition containing as an active ingredient at leastone ester of an acid of the group consisting oi2.4-dichlorophenoxyacetic acid and 2.4.5-trichlorophenoxyacetic acidwith an ether alcohol of the formula R.O.CH2.CH:OH, wherein R is 01' thegroup consi ting of methyl, ethyl, propyl, butyl, benzyl and phenyl, aidactive ingredient being present in phytocidal concentration. 2. Aherbicidal composition containing as its active ingredient a mixture ofesters of acids oi. the group consisting of 2.4-dichlorophenoxyaceticacid and 2.4.5-trichlorophenoxyacetic acidwith an ether alcohol 01' theformula R.O.CH2.CH2OH, wherein R is of the group consisting of methyl,ethyl, propyl, butyl, benzyl and phenyl, said active ingredient beingpresent in phytocidal concentration.

3. A herbicidal composition containing as an active ingredient at leastone ester of an acid of the group consisting of2.4-dichlorophenoxyacetic acid and 2.4.5-triehlorophenoxyacetic acidwith 6 an ether alcohol of the formula R.O.CH2.CH2OH, wherein R isbutyl, said active ingredient being present in phytocidal concentration.

4. A herbicidal composition containing as an active ingredient at leastone ester of an acid of the group consisting of2.4-dichlorophen0xyacetic acid and 2.4.5-trichlorophenoxyacetic acidwith an ether alcohol of the formula R.O.CH2.CH2OH, wherein R is ethyl,said active ingredient being present in phytocidal concentration.

5. A herbicidal composition containing as an active ingredient at leastone ester of an acid of the group consisting of2.4-dichlorophenoxyacetic acid and 2.4.5-trichlorophenoxyacetic acidwith an ether alcohol of the formula R.O.CH2.CH2OH, wherein R is methyl,said active ingredient being present in phytocidal concentration.

6. A herbicidal composition containing as an active ingredient the2-butoxy ethanol ester of 2.4-dichlorophenoxyacetic acid, said activeingredient being present in phytocidal concentration.

7. A herbicidal composition containing as its active ingredient amixture of the 2-butoxy ethanol ester of 2.4-dichlorophenoxyacetic acid,and of the 2-butoxy ethanol ester of 2.4.5-trichlorophenoxyacetic acid,said active ingredient being present in phytocidal concentration.

WILLIAM W. ALLEN.

REFERENCES crrnn The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,974,810 Dvornikofi Sept. 25',1934 2,142,126 Grether Jan. 3, 1939' 2,166,557 Stoesser July 18, 1939-2,390,941 Jones Dec. 11, 1945 2,396,513 Jones Mar. 12, 1946 2,523,227Mullison Sept. 19, 1950 2,537,228 Mullison Sept. 19, 1950

1. A HERBICIDAL COMPOSITION CONTAINING AS AN ACTIVE INGREDIENT AT LEASTONE ESTER OF AN ACID OF THE GROUP CONSISTING OF2,4-DICHLOROPHENOXYACETIC ACID AND 2.4.5-TRICHLOROPHENOXYACETIC ACIDWITH AN ETHER ALCOHOL OF THE FORMULA R.O.CH2.CH20H.. WHEREIN R IS OF THEGROUP CONSISTING OF METHYL, ETHYL, PROPYL, BUTYL, BENZYL AND PHENYL,SAID ACTIVE INGREDIENT BEING PRESENT IN PHYTOCIDAL CONCENTRATION.